Telegraphic signal transmitter



w. GLASER.

. TELEGRAPHIC SIGNAL TRANSMITTER.

APPLICATION FILED JAN- 13.1922.

Patgantd Nov. 2 ,192.

Patented Nov. 28, 1922.

UNITED STATES PATENT orrrcs.

WILLIAM GLASER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 ALBERT G. MoCALE-B, OF

CHICAGO, rumors.

TELEGRAPHIC sreuar. rasnsnrr'rna.

Application filed January 13, 1922. Serial No. 528,942.

To alt whom it may concern:

Be it known that I, VILLIAM GLAsnn, a

I citizen of the United States, and resident mitters, of which thefollowing is a full,

clear, concise, and exact description, reference being had to theaccompanying'drawings, forming a part of this specification.

My invention relates to a device suitable for use by telegraphers.Generally stated, it is the object of my invention to provide a devicethat will eliminate certain serious shortcomings of telegraphic signaltransmitting devices now in general use.

The majority of telegraphictransmitting devices now in use comprise twosets of contacts, one set of contacts being manually operated to effectthe transmission of current impulses corresponding to dashes, the otherset of contacts being operated by a vibrator, which is set in operationby the operator when he wishes to transmit current impulsescorresponding to dots.

My invention is particularly concerned with certain improvementsapplicable to devices of this general type.

In the accompanying drawings illustrating my invention,

Figure 1 is a top plan view ofa telegraphic signal transmitter embodyingmy invention;

Figure 2 is a transverse section which may be regarded as taken on theline 22 of Figure 1, and looking in the direction indicated by thearrows;

Figure 3 is a detail elevationtaken on the line 3-3 of Figure l, andlooking in the direction indicated by the arrows; and

Figure 4; is a circuit diagram.

Referring now to Figures 1 and 2, reference numeral 10 indicates a metalbase plate which, if desired, may be provided with legs or buttons 1O1() of insulating material. The base plate 10 carries two binding posts11 and 12, which may be of any suitable construction. The binding post11 is preferably insulated from'the base plate 10,and the binding post12 is preferably in electrical contact'.withthe base plate; The bindingpost 11 is connected by a jumper 13 with the lower end of a conductingpost 14, which is carried by, but suitably insulated from, the baseplate 10. Adjustably mounted in the upper end of the conducting post 14is a screw 15, which is provided with a contact 16, the contact 16 beingthe stationary dot contact. Conducting post 14 is electrically connectedby a jumper 1'7 with a second conducting post 18, the conducting postl8being carried by, but insulated from, the plate 10. Adjustably mountedin the upper end of the conducting post 18 is a screw 19, which carriesthe contact 20. The contact 20 is the stationary dash contact. i

Mounted upon the base plate 10 is a metal bridge 21 which supports alever 22 for movement in a horizontal plane around a vertical axiscoincident with the center of screw 23. Bridge 21 is provided with arms21, and 21 said arms being provided respectively with screws 24.- and25, which define the limits between which the lever 22 may be moved. Acompression'spring 26 acts between the long arm oflever 22 and a screw27, carried by the bridge arm 21 said spring normally holding the longarm of lever 22 in engagement with the screw 24.

Normally disposed in substantial alignment with the lever 22 and carriedthereby is an oscillating. arm-28, which is provided with a weight 29which may be adjusted longitudinally of the vibrating arm and secured atany desired position thereon.- The vibrating arm 28 is connected to andsupported from the long arm of lever 22 through a leaf spring 30, whichhas one of its ends rigidly secured to the longarm of lever 22, and itsother end rigidly secured to the adjacent *enol of'the vibrating arm 28.Fixed to the vibrating arm 28, preferably near the point of itsattachment to the spring 30, is a substantially U-shaped leaf spring 31,which at its free endis provided with a contact 32, the member 32constituting the movable dot contact.

At 33 I have illustrated a roller which is adapted to bring thevibrating arm 28 to rest when the long arm of lever 22 lies against thescrew 24. The roller 33 is pivoted to one end of a substantiallyL-shaped lever 34, which bridges the free end of vibrator arm 28 and hasits'other end pivotally mounted in a suitable bracket 35. When the lon25, the roller .33 does not interfere with vibration of the vibratingarm 28. It'should be noted that if the free end of the viarm of lever 22lies against the screw I bratingarm 28 ismoved forcibly into contactwith the roller 33; the lever 34will turn on its pivot, the roller-being lifted against gravity by reason of its contact with thevibrating arm.

I now call attention to the actuating lever 36, which is provided with afinger piece 37, the latter being preferably formed of insulatingmaterial. One end of the operating lever 36 normally lies snugly incontact witht-he short arm of lever 22, and is held yieldingly insuchcontact by a compression spring 38, which is disposed around a screw 39,and acts between the short arm 1510f 1ever'22 and an adjustable collarcarried by such screw. The screw'39 is fixed to the operating lever 36,and extends freely through an opening in the short arm of lever 22. Saidopening is indicated by dotted .lines in Figure 1. It will be understoodthat this opening has a diameter greater than the diameter of screw 39,so that the operating lever 36 may move relatively to the lever 22 inthe manner presently to be explained. The operating lever is pivoted bya pin 40 for movement around a vertical axis, ,determinedrb'y such pin.The pin 40 preferably extends through the lever 36,-an-d bears in abracket member 41, which is lined .to the long arm of lever 22 at apoint adjacent the pivot of said lever22.

The actuating lever 36 carries a contact 42 which constitutes themovable dash contact. It will be understood of course, that the contact42 is grounded to the frame 10,

and that the movable dotconta'ct is likewise'groundedto the frame 10. At43 is indicated afknife switch which is'always open when the instrumentis in use, the switch .40 being closed only when the stationary contacts16 and 20 are to be grounded to the framelO.

It willbe understood that when the actu ating lever 36 is moved in aclockwise three-- ::45 tion (as vlewed in Figure ,1) the actuating leverwill turn'on its-pivot pin lLto permit the iinovable fdash contact to.engage its associated stationary contact. thespring 26 holds "the lever22 in engage- ,50 inent withscrewQd, the spring 38 yielding -to ,ebermitthe actuating ,lever 36 to move relatively to .the lever 22. \Vhentheactuat ing lever 36 is IIIOVGCl in a, counterclockwise 1 direction (asviewed in Figure 1) the long 155 arm oflever 22 ismovedout ofengagementwith screw 2,4 and into engagement with sscrew 25. The vibratingarm 28no longer lies'in engageinent withrolleri33, and such arm is .free tovibrate,the periodicity of its 160 VlblfitlOll being determined by theadjust- I thi case, mounted upon fixed binding post 11.

shown in the accompanying drawings need not differ essentially fromwell-known types of telegraphic transmitters now in use. The specificmechanism illustrated in the accompanying drawings is in many respectssimilar to the well known Martin vibroplex, which is well-known to allpersons familiar with modern telegraphic apparatus.

I shall now describe those elements oi. the herein illustrated devicewhich are the salient features of my present invention. Can ried by thevibrating arm 28 and conveniently. secured to or torn ed integral withthe collar which also carries the ii-shaped spring 31.1s a metal blockA. which ronof the core being ,adjustably secured by nuts 7f in an rp-turned portion of a bracket G. The bracket G is pivotally mounted atIt, upon one end of an arml, the other end of which is supported on thebinding post 12. It will thus be seen that the electromagnet may beadjusted toward and away from the armature A by turning theelectromagnetaroundthe vertical axes determined by the screw 71.", andthe binding post 12. Further adjustn'ient may be see cured by properlypositionin the nuts f- 7'. One terminal of the electroin let winding 0is connected with the binding post-12. The other terminal of theelectromagnet winding is connected with a binding post J, which isconveniently mounted u-pon one end of an insulating block K, which hasits other end binding posts J and 11 are adapted to be connecteddn vanysuitable telegraph circuit by leads indicated at L-L.

In modern long-distance telegraph work,

,it is very" desirable that all of the current impulses corresponding todots be of uniform duration, and it is also highly important that anyseries of short impulses corresponding to a series of dots occur withabsolute regularity. This is true because in long-distance telegraphsystems it is necessary to employ dehcate repeating and receivingapparatus, .WlllCll w1ll respond properly only to dot impulses which areof adefinite duration, andwhich when sent in a series occurwithregularity.

.I ,findithat inIthe ordinary transmitter of form of electromagnetherein The ' occur with regularity.

tion. Let us assume that the actuating lever 36 is moved inacounter-clockwise direction (as viewed in Figure 1). As soon as thevibrating arm 28 begins to vibrate, the con tact 82 engages the contact16 to causethe transmission of a dot impulse. As soon as the contactsclose, the electromagnet B is energized and attracts itsarmature A,thereby tending to separate the dot contacts. rate, the electromagnet Bis de-energized. I find that so long asthe lever 22 is held inengagement with the screw 25, the vibrator28 of the device of myinvention will continue to vibrate with a definite and constantamplitude. Therefore the dot impulses are of uniform duration and occurwith absolute regularity.

Prior to sending messagesover the longdistance telegraph line, it isordinarily necessary to send over the line a long series of dot impulsesto permit the proper adjustment of the various receiving and re peatingdevices. For best results, it is desirable that these dot impulses be ofuniform duration and occur in a long, unbroken series. It is possible tosecure a long, unbroken series of dot impulses by the use of the deviceof my invention, because the vibrator 28 continues to vibratewithconstant amplitude so long as the lever 22 is held in, engagement withthe screw 25. With the ordinary telegraphic signal transmitter of thevibrator type, it is practically impossible to secure an unbroken seriesof more than approximately 12 or 15 dots, and even these do not occurwith that degree of regularity, and are not characterized by thatuniformity of duration which my experience has demonstrated as necessaryto best results in modern long-distance telegraphic communication.

It will be noted that in the operation of the device of my invention,the electromagnet B is energized each time the dash contacts are-closed,as well as each time the dot contacts are closed. Now let us assume thatthe dash contact 42 is moved manually into engagement with thestationary contact 20. The electromagnet B is energized and the armatureA is drawn over into engagement with or in close proximity to theadjacent end of the electromagnet coree. Lever 34 yields to permit suchmovement. As a result of this movement, the vibrating arm 28 is movedaway from the stationary dot contact the spring 30 As soon as the dotcontacts sepa being stressed. Now as soon as the dash contacts areseparated, thereby de-energizing the electromagnet, the vibrating arm 28swings quickly toward the stationary dot contact due to the energystored in spring 30. This arrangement is of great advantage becauseimmediately after the cessation of the dash impulse the vibrator arm 28will swing quickly to efiect the sending of a dot impulse or a series ofdot impulses. The distance through which the vibrator arm 28 must movebefore effecting the sending of a dot impulse following a dash impulseis sufficiently great so that the operator may, if he desires, send twoor more dash impulses without trans mitting any intervening dotimpulses.

The electromagnet B. of the device of my invention is, of course,energized by the signaling current flowing in the circuit controlledbythe dot and dash contacts.

Having thus illustrated and described a preferred embodiment of myinvention, I do not limit myself to the specific construc tion andarrangement of parts herein shown and described, but wish to cover allequivalent arrangements falling within the terms and spirit of theappended claims.

What I claim is new and desire to secure by Letters Patent of the UnitedStates is:

l. A telegraphic signal transmitter comprising normally separated dotcontacts, a

vibratory member adapted when vibrating to effect the engagement anddisengagement of said dot contacts, manually operable mechanical meansfor initiating vibration of said vibratory member, an electromagnetadapted when energized to attract said vibratory member, and circuitconnections whereby said electromagnet is energized when said dotcontacts are in engagement, and deenergized when said contacts areseparated.

2. In combination with a telegraph circuit, a pair of normally separateddot contacts, adapted when operated to. complete and interrupt saidcircuit, a vibratory member adapted when vibrating to cause theengagement and disengagement of said contacts, manually operable meansfor initiating vibration of said vibratory member, and electromagneticmeans for maintaining the amplitude of vibration of said vibratorymember constant, said electromagnetic means comprising a magnet windingincluded in said circuit.

3. In combination with a telegraph circuit, a pair of normally separateddot contacts, adapted when operated to complete and interrupt saidcircuit, avibratory member adapted when vibrating to cause the engagement and disengagement of said con tacts, manually operablemechanical means for initiating vibration of said vibratory member, andelectromagnetic means for maintaining the amplitude of vibration of saidvibratory member constant, said electromagnetic means comprising amagnet winding included in said circuit, together with a pair ofnormally separated dash contacts that are manually operable to completesaid telegraph circuit.

a. Means or transmitting telegraph signals comprising a vibratorymember, a member from which said vibratory member is supported, aflexible leaf spring connecting said members, a pair of normallyseparated co-operating dot contacts, one of said contacts beingstationary, the other of said con tacts being carried by the vibratorymember, a telegraph circuit controlled by said dot contacts, saidmovable dot contact adapted to engage and disengage the stationary dotcon tact as said vibratory member vibrates, manually operable means forinitiating vibration of said vibratory member, and an electromagnetexcited by the current traversing said circuit when said dot contactsare in engagement, said electromagnet adapted to maintain the amplitudeof vibration of'said vibratory member substantially constant, byattracting the vibratory member away from the stationary dot contact.

5. Means for transmitting telegraph sig nals comprising a vibratorymember, a member from which said vibratory member is supported, aflexible leaf spring connecting said members, a pair of normallyseparated co-operating dot contacts, one of said contacts beingstationary, the other of said contacts being carried by the vibratorymember, a pair of normally separated manually operable dash contacts, atelegraph circuit controlled by said dot contacts and said dashcontacts, said movable dot contact adapted to engage and disengage thestationary dot contact when the vibratory member vibrates, manuallyoperable means for initiating vibration of said vibratory member, andelectromagnetic means adapted to maintain the amplitude o1 vibration ofsaid vibratory member substantially constant, said electromagnet beingexcited by current flowing through said circuit as a result of theengagement oi the dot contacts or dash con tacts, prolonged excitationof said electromagnet resulting from the engagement of said dashcontacts serving to stress the spring by means of which said vibratorymember is mounted.

6. In a device of the class described, :1 vibratory member which, whenset in motion, will continue to vibrate for a considerable time,manually operable mechanical means for initiating vibration of saidvibratory member, a pair of normally separated dot contacts operated bysaid vibratory member, an electromagnetic positioned adiacent saidvibratory member, an armature for said electromagnet carried by saidvibratory member, and a telegraph circuit including said dot contactsand said electromagnet whereby said electromagnet is energized andde-ener gized as the ,dot contacts engage and disengage due to themovement or" the said vibratory member.

In witness whereof, I hereunto subscribe my name this 9th day ofJanuary, 1922.

